Train dispatching system for railroads



June 1, 1937. v Q DlCKE r AL 2,082,152

TRAIN DISPATGHING SYSTEM FOR RAILROADS Filed March 13, 1929 2 Sheets-Sheet 1 FIG.1.A.

June 1937- o. H. DICKE ET AL 2,082,152

TRAIN DISPATCHING SYSTEM FOR RAILROADS Filed March 15, 1929 2 Sheets-Sheet 2 v M M ATTORNEY Patented June 1, 1937 UNITED, STATES TRAIN DISPATCHING SYSTEM FOR RAIL- ROADS Oscar H. Dicke and Forest B. Hitchcock, Rochester, N. Y., assignors to General Railway Sig nal Company, Rochester, N. Y.

Application March 13, 1929, Serial no. 34632731 23 Claims.

This invention relates to train dispatching systems, and more particularly to a system in which a plurality of switch machines and wayside sig- 4 nals are controlled and O. S. indications are 5 transmitted by sequentially closed channel or message circuits carried over the same line circuit.

In a selector system of the kind mentioned, suitable apparatus is located at a dispatchers ofiice and suitable apparatus is located at all way stations, these apparatuses being connected in such a way as to close distinctive channel or message circuits extending from the dispatchers office to the various way stations sequentially. v A

125 system of this kind may for convenience be called a synchronous selector system.

In the prior application of O. H. Dicke, Serial No. 180,475 filed April 2, 1927, a large number of control circuits are momentarily closed sequentially by rotating arms located at the dispatchers ofiice and at each of the way stations, these rotating arms being rotated in synchronism and being connected by a line wire so that distinctive channel circuits are set up one after another,

suitable means being provided to transmit control influences over such momentarily completed channel circuits. In accordance with the present invention it is proposed to use a series of channel selecting relays at the dispatchers 011106, and

a series of channel selecting relays located at the various way stations along the railway track, these two groups of relays being operated in synchronism so that corresponding relays of each 7 group change simultaneously, so that contacts of these relays may be used to complete channel or message circuits sequentially. Putting it another way, the dispatchers ofiice, in accordance with the present invention, is provided with a large number of channel selecting relays, say twelve in 40 number, and similarly there are four channel selecting relays at each of the way stations also making a total of twelve. These relays are so interconnected that when the first relay at the dispatchers office is operated, the first relay at 45 the first way station is operated. Similarly, when the second relay at the dispatchers office is operated, the second relay at the first way station is operated, and soon, so that when the last or twelfth relay in the dispatchers oflice is so operated the fourth relay at the third way station is simultaneously operated. By this arrangement the sum of the channel selecting relays located at the way stations is the same as the number of channel selecting relays constitut- 55 ing the relay bank at the dispatchers oflice, but if desired there may be more relays in the office group than are. used in the way station group as pointed out hereinafter.

Other objects, purposes and characteristic 60 features of the invention are in part apparent from the accompanying drawings and are in part pointed out in the description hereinafter.

In describing the invention in detail reference will be made to the accompanying drawings in which Fig. 1A illustrates the apparatus located in the dispatchers office, and Fig. 13 illustrates the apparatus located at the first and second way station of the railway system, these Figs. 1A and 13 preferably being laid end to end to constitute the entire system. l

Referring to Fig. 13 wherein there has been shown a passing siding PS of a single track railway system, signaled with absolute-permissiveblock signals, of which only thestarting signals 2, 2 1 and 1 and the entering signals l, I 8 and 8 have been shown. These signals are controlled jointly by trackrelays, stick relays and. tumble-down circuits, as well as by suitable control relays controlled through the medium of the synchronous relay selector system embodying this invention, and are preferablyv further controlled in accordance with the position of the associated switch machine SM OnSM Referring to the left hand portion of Fig. 1B. the switch machine SM is controlled by the. switch machine relay SMR as conventionally shown by dotted line, suitable approach locking and detector locking means being employed as. shown in the prior application ofS'. N. Wight, Serial No. 120,4:23 filed July 3, 1926. Similarly the switch machine SM is controlled by the switch machine control relay SMR Thesignals l, N, 8 and 3 are controlled by the control relays SR and DB and the signals l, I 2 and 2 are controlled by the control relays SR. and DR as more clearly described in the prior patent to S. N. Wight, Patent No. 1,889,457 dated November 29, 1932. The track switch operated by the switch machine SM is preferably provided with the usual detector track circuit including the detector track relay TR and similarly there is provided a detector track circuit at the east end of the passing siding PS containing a detector track relay TRF.

Referring now to Fig. 1A of the drawings, which shows the dispatchers ofiice, the outlying passing siding PS has been reproduced in miniature by the passing siding ps of a suitable miniature track layout simulating the entire railway system. At the east end of this miniature passing siding pc is shown an indicating lamp i which in accordance with the present invention, is illuminated when the track relay TR, is de-energized, and similarly there is an indicator I located at the west end of the miniature passing siding ps for indicating the occupancy of the detector track circuit located at the west end of the passing siding PS. This miniature passing siding ps is preferably located over the dispatching machine containing a large number of switch machine and signal levers, of which the signal lever LS and the switch machine lever LSM are associated with the west end of the passing siding ps, and the levers LS and LSM are associated with the east end of the passing siding ps.

The dispatchers office apparatus (entire Fig. 1A) is connected to the first way station (left hand portion of the Fig. 1B) by a message wire In, a first stepping wire H, a second stepping wire I2 and a common return wire l3. Similarly, the first way station is connected to a third Way station by similar wires.

In the dispatchers oifice are located 3 relays, RLR, MR and LR, conveniently called the impulse generating relay group. These relays are so interconnected that the relay RLR controls the relay MR, the relay MR controls the relay LR, and the relay LR controls the relay RLR to the opposite position from which it occupied when it last controlled the relay MR, so that a sort of non-mechanical or electrical rotation of these relays RLR, MR, and LR takes place, this rotation discontinuing when the knife switch I9 is opened. If desired the relay RLR may be omitted, which if the other relays have the same operat ing period speeds up the system. It is thus seen that the line relay LR the dispatchers line relay DLR and the line relay LR all three of which are connected in series will be alternately operated from one energized position to the other energized position. The dispatchers line relay DLR controls the dispatchers relay group comprising channel selecting relays A, B, C, D, E, F, G. Similarly the line relay LR controls the relay group at the way station containing relays A B and C It will be noted that the line relay LR is not connected in series with the dispatchers line relay DLR until the relay C has been operated, but that the line relay LR when operated may control the relays D E and F From the foregoing description of the relays it readily appears that many different combinations of relay positions may be set up in sequence and that many diiferent channel circuits can be momentarily completed sequentially, so as to con stitute a synchronous selector system employing sequentially operated channel selecting relays instead of rotating contact arms. With this general understanding of the system and the specific apparatus involved, it is believed expedient to describe the operation of the system; this in order to understand the particular circuit arrangement selected to illustrate the invention and the manner in which the various relays coact to set up the various channel circuits sequentially.

Operation-This apparatus will remain at rest so long as the knife switch i9 is open. All of the polar relays illustrated in the drawings are for conventional purposes so wound that if current flows in at the left hand terminal and out of the right hand terminal of such relay this current fiow in co-operation with the magnetism of a permanent magnet associated with such relay will cause its contact to be moved toward the right. In other words, in the convention adopted the application of current of positive polarity to a polar relay moves its contacts toward the right and the application of negative current to the relay causes its contacts to be moved toward the left. Also, in the convention adopted those polar relays in which the movable contacts are shown pendant, that is in a neutral position, are to signify that the particular relay is biased to its neutral position, whereas those relays in which the contact assumes either the right hand or the left hand extreme position and the neutral position has not been illustrated signifies that such relay is a polar relay of the magnetic stick type, in which the permanent magnet holds the contacts in the position to which they were last operated.

With these conventional representations in mind, closure of the switch I9 causes the contacts 29 and 2! of the master relay MR tobe moved to the right, because under this condition the positive terminal of the battery 25 is connected to the left hand terminal of relay MR through the medium of contact 24 of the relay RLR. With the contact in its right hand position positive current is applied to the line relays LR, DLR and M3 in series through the following circuit-beginning at the positive terminal of battery 25, wires 26 and 21, contact 20, wire 23, winding of relay LR, Wire 29, winding of the relay DLR, wire Ell, contact 31 of the relay G assuming its right hand position, first stepping wire H, contact 32 of the relay C assuming its right hand position, wire 3-3, winding of line relay LR wire 34, to common return wire I3, connected to the mid point of the battery 25. It is thus noted that so long as the circuit just traced is not changed by operation of either the group relay G or the group relay C that the line relay LR, DLR and LR will be operated synchronously to the right and left hand positions by repeated reversals of the contact 223 of the master relay MR.

With the line relay LR in its right hand position current of negative polarity is applied to the repeater line relay RLR through the medium of contact 35 of the line relay LR. This application of negative current to the repeater line RLR causes current of negative polarity to be applied to the master relay MR, thereby causing the master relay to be operated to the left hand extreme position. It is thus seen, that the relays RLR, MR, and LR will be operated through a cycle of non-mechanical rotation, so that these relays will be alternately operated to their right hand and their left hand extreme position, so long as the switch l9 remains closed.

It is thus seen that the line relays LR, DLR, and LR are alternately operated to the right and to the left in synchronism, so long as the circuit connecting these line relays in series is not broken. Let us first observe What effect the dispatchers line relay DLR will have upon the dispatchers channel selecting relays A to G, inclusive, and then let us observe what effect the line relay LR will have upon the channel selecting relays A B and 0 With the dispatchers line relay DLR operated to the right hand position, current will flow from the positive side of the battery 40, through the contact 39 of relay DLR, contact 4! of the channel selecting relay G assuming the right hand position, then through the contact 42 of the channel selecting relay A assuming the right hand position through the winding of the relay A to a common return wire it connected to the mid-point of battery 4B. The flow of this current being of positive polarity will have no effect upon the relay A, and the relay A Will remain in the right hand position. For reasons already given the line relay DLR will only assume its right hand extreme position momentarily and will then be operated to itslefthand position, in which case the negative terminal of the battery 4! is connected to the channel selecting relay A, through the circuit just traced, and this negative application of current to the relay A will cause it to be operated to its left hand position, wherein it is held by permanent .magnet stick action. By operation of relay A to the "left hand position the shifting of its contact 42' will apply current of negative polarity to the relay B through the medium of contact 43 of the relay B. Since the relay B already assumes the left hand position this application of current .of negative polarity thereto will not cause operation thereof. The line relay DLR is, however, after a very short period of time again operated tothe right hand extreme position in. which case current of positive polarity is applied to the winding of the re lay B through the medium of .contact 43 of relay B. This application of current of positive polarity to the relay B will cause this relay B to be operated to its right hand position, by reason of which its own energizingcircuit is broken and the circuit just mentioned is connected to the relay C through the medium of contact 44 of the relay C. Since this current, however, is of positive polarity and the relay C already assumes the right hand position this'application of current will not opcrate the relay C. The line relay DLR will, however, be operated to the left hand position at the next step of operation, and will apply current from the negative side of the battery 40 to the winding of the relay C through the medium of contacts 39, 4|, 42, 4.3, and 44, and. this application of current of negative polarity to the relay C, will cause it to be operated to its left hand position. It is thus seen that operation of the line relay DLR to the right then to the left then to the right and then back to the left has caused operations of the relay A to the left, relay B to the right, and relay C to the left. Let us now see how these same 4 impulses applied to the line relay LE connected in series with the line relay DLR, will produce operations of the channel selecting relays A B and C As assumed, the first impulse flowing through the line relays in series will operate the line relay LE toward the right, thereby causing the positive side of the battery 45 to be connected to the channel selecting relay A through the medium of contacts 46 of the relay LR 4'! of the relay C in its right hand position,-and contact 48 of the relay A in its right hand position. This application of positive current to the relay A will not cause operation of this relay A because it already assumes the right hand position. The second current impulse flowing through the line relay LE DLR and LR in series is of negative polarity, and causes these line relays to be operated to their left hand position, in which case current of negative polarity is applied to the relay A through the medium of contacts. 46, 4 1, and 48, and this application of current of negative polarity causes the relay A to be operated toward the left, whereby the contact 48 of relay A is shifted, and the circuit in question is connected to the relay B through the medium of contact as of relay B assuming the left hand position. This application of current of negative polarity to the winding of the relay B will, however, not affect operation of this relay B because it already assumes the left hand position. The next impulse impressed upon the line relay LR is one of positive polarity, thereby moving the contact 46 to the right and applying current of positive polarity to the relay B thereby causing this relay B to be moved to the right, breaking its own energizing circuit and connecting the circuit in question to the winding of the relay C through the medium of contact 55] of the relay C By this application of current of positive polarity to the Winding of relay C the relay 0 will not be operated, because it already assumes; the right hand position.

The next impulse impressed upon the linerelay LR is one of negative polarity, thereby "moving the'conta-c't '46, to the left and applyingcurrent of, negative polarity tothe relay G which causes this relay C to be moved to the left, breaking its own energizing circuit. The operation of the relay C disconnects the line relay LR and passes the impulses to the, succeeding station as hereinafter explained,

It is thus seen that channel selecting relays A and A are simultaneously operated toward the left, the channel selecting relays B and B are simultaneously operated toward the right, and the channel" selecting relays C and C are simultaneously operated to the left and from which it isunderstood that the relays A, B, C, and A B and C are operated in non-physical rotation-in synchronism, and that contacts of these relays.

combination with contacts of adjacent relays may be used to control channel circuits of the synchronous selector system of which they form apart. These channelcircuits will be discussed in connectionwi-th the transmission of messages both control messages and. controllingdistant switch machine and signal and indication mechanisms. for indicating in the d-ispatchers ofiice the occupancy of track circuits alongthe railway track.

Having now considered how the relays A, B, anda-C, and the relays A B and C are operated in synchronism, let us consider how the relays D, E, and .F, and relays D and E and F are operated insynchronism. The last operated position of the line relays DLR and LR was the left hand position, in which these line relays operated the relay C and C to the left hand position. It should be noted that this operation of the relay C to its left hand dotted position interrupted the line circuit heretofore traced including the relays. LR, DLR. and LE in series at the contact 32 of the relay C disconnecting the line relay LE and connecting the wire H to the Wire l5, which wire t through contact 54 of relay F is connected to the winding of the line relay LR so that the next impulse applied to the line circuit will flow through the line relays LR", DLR and LR?- in series, this. next line impulse is one "of positive polarity and causes the line relays :DLR and .RL to be moved toward the right. Current may flow to the relay D from the battery 40, through the .medium of contacts 39 of relay DLR toward the right, contact 4| of relay G, in its right hand position, contact 42 of relay A in its left hand position, contact '43 ofrelay B in its right hand position, contact 44 of relay C in its left hand position, and contact 56 of relay D in its left hand position, thus operating the relay D to'its right hand position. Similarly operation of the line relay LE to its right hand position, causes .current to flow from the positive side of battery .55, through the contact 53 of relay LE contact 60 of relay F assuming its left hand po sition, through contact 5! of the relay D assuming its left hand position to the winding of this relay D2. This application of current of positive polarity to the relay D causes it to be operated to its right hand position, as a. result of which the circuit in question is shifted to the relay E through the medium of contact 52, but since this relay E already assumes the right hand position it will not respond to this flow of current of positive polarity.

The next impulse applied to the line relays LR, DLR and LR in series, is of negative polarity, thereby causing these line relays to be operated toward the left. With the line relay DLR now assuming the left hand position, current of negative polarity is applied to the relay E, from the battery 4 through the Contact 39 of relay DLR, contact 4| of relay G, to the right, contact 42 of relay A to the left, contact 43 of relay B to the right, contact 44 of relay C to the left, contact 55 of relay D to the right and contact 57 of relay E in its right hand position to the winding of relay E thereby operating the relay E to the left hand position, and continuing the circuit in question through the contact 58 of the relay F to the winding of the relay F. This relay F, however, already assumes the left hand position so that it will not be operated until the line relay DLR. is moved back to its right hand position. Similarly, operation of the line relay LE to its left hand position causes current of negative polarity to be applied to the relay E from the battery 55, through contact 53 of relay LE to the left, contact 69 of relay F to the left, contact of relay D assuming the right hand position, contact 52 of the relay E assuming its right hand position, whereby the relay E is operated toward the left and shifts the circuit in question to the winding of the relay F through contact 5| of this relay, but since the current is of negative polarity the relay F is not operated.

The line relays DLR and LE are now operated toward the right, under which condition current of positive polarity from the battery 4 may flow to the winding of the relay F through the contact 59 of the relay DLR to the right, contact 4| of the relay G assuming its right hand position, contact 42 of the relay A to the left, contact of the relay B to the right, Contact 44 of the relay C to the left, contact 56 of the relay D to the right, contact 51 of the relay E to the left, contact 58 of the relay F assuming its left hand position, through the winding of relay F to the common connection of the battery, Whereby relay F is operated to its right hand position. Similarly, operation of the line relay LR to its right hand position applies current of positive polarity from battery 55 through contact 53 of relay LE contact 6 of relay F assuming its left hand position, contact 5| of relay D assuming its right hand position, contact 52 of relay E assuming its left hand position, contact 6| of relay F assuming its left hand position, to the winding of this relay F thus operating the relay F to its right hand position. This operatic-n of the relay F to its right hand position disconnects the line relay LR and connects the line relay of the next way station (not specifically shown). Impulses applied to the first stepping circuit will not operate any of the relays at either the first or the second way station hereafter, but if impulses are applied to the second stepping circuit the relays are again operated sequentially as hereinafter explained from which it appears that if the relays at the way stations should lose or gain one or more steps they will be automatically brought back in step upon shifting of the control from the first stepping line to the second stepping line, as presently described.

In the operation as thus far considered, the repeated reversals of the master relay MR caused the relays A, B, C, D, E, and F and the relays A B C D E and F to be successively operated from their solid line to their dotted line position, the relays A and A being operated first and the relays F and F being operated. last during each half cycle. The next impulse that is applied to the line circuit is a negative impulse and operates the relay DLR to the left hand position, and causes the relay G to be operated to the left hand position through the following circuit:--beginning at the negative terminal of the battery 4&3, contact 39 of the relay DLR in its left hand position, contact 4| of the relay G in its right hand position, contact 42 of relay A toward the left, contact 43 of the relay B toward the right, contact 44 of the relay C toward the left, contact 56 of the relay D toward the right, contact 51 of the relay E toward the left, contact 58 of the relay F toward the right through the contact 59 of the relay G and the winding of this relay to the mid-point of battery 4. This impulse causing the relay G to be operated to its left hand dotted position. The shifting of the relay G to its dotted position causes the contact 3| to connect the line wire 30 from the first stepping wire II to the second stepping wire I2, and with negative current still applied to the line wire 35 it may flow through the contact 3| in its left hand position, through wire l2 through the contact in in its left hand position, through wire to the winding of relay LR wire 34 and common return wire l3, back to the battery 25. But this application of current of negative polarity to the line relay LR will not cause operation of the relay A through the contact 46 of relay LR in its left hand position, and contact 41 of relay C in its left hand position, and contact 1| of the relay A in its left hand position to the winding of relay A because this relay A already assumes the position to which current of negative polarity would operate it. In other words, the relay G in the dispatchers office has been operated to shift the stepping impulses to the second stepping wire, but this stepping impulse has not caused operation of any of the relays A B C D E and F at the way stations.

The master relay MB is next operated to the right, in which position current from the positive side of battery 25 may flow through the line relays LR", DLR, and LE for reasons just given, namely because relay G now assumes the left hand dotted position. With the line relay DLR operated to its right hand position current of positive polarity is applied to the relay A through the following circuit-beginning at the positive terminal of battery 40, contact 39 of the relay DLR. to the right, contact 4| of the relay G, toward the left, contact 63 of the relay A to the left, thus operating the relay A to its right hand position, and thus breaking the circuit just traced and shifting it to the winding of the relay B, which will not be operated. Similarly, operation of the line relay LR. to its right hand position, causes current to flow from the positive side of the battery 45, through contact 46 of the line relay LE to the right, contact 4! of relay C to the left, contact 7! of relay A to the left, through the winding of this relay A back to the midpoint of battery 45, thus causing the relay A to be operated toward the right, in which case the circuit just traced is shifted to the relay B which relay B is not operated for obvious reasons.

The line relays DLR and LR are next operated toward the left. This causes the relay B to be operated toward the left through the following circuit:beginning at the negative terminal of battery 40, cont-act 39 of relay DLR to the left, contact 4| of relay G to the left, contact 63 of relay A to the right, and contact 54 of the relay B to the right, and causes the relay B to be Operated toward the left. Similarly the channel selecting relay B 'is operated in response to'operation of relay LR. to the left through the following circuitz-beginning at the negative terminal of the battery 45, contact 46 of the line relay LE to the left, contact 41 of the relay C "to the left, contact :1 I of the relay A to the right, and contact 12 of the relay B to the right, thus causing the relay B to be operated toward the left.

The relays DLR. and LR. are next operated toward the right, in which case relay C is operated toward the right through the following circuit:-beginning at the positive terminal of battery-40, contact 39 of relay DLR tothe right, contact 4| of relay G toward the left, contact 63 of relay A toward the right, contact 64 of relay B toward the left, contact 65 of relay C toward the left, thus causing the relay C to be operated toward the right. The relay C is operated toward the right through the following circuit:

beginning at the positive side of battery 45, contact 46 of relay LE. to the right, contact 4'! of the relay C to the left, contact ll of the relay A to the right, contact 12 of the relay B to the left and through contact 50 of the relay C to the left, through winding of the relay C thus causing the relay C to be operated toward the right, and thereby shifting the contact Hi from its dotted to the solid line position and substituting the line relay LR, for the line relay LR in the second stepping circuit.

The line relays DLR and LIB/ are next operated toward their left hand position, in response to which the relay D is operated to the left through the following circuit:beginning at the negative terminal of battery 46, contact 39 of relay DLR to the left, contact 4| of relay D to the left, contact 63 of relayA to the right, contact 64 of relay B to the left, contact 65 of relay C to the right, contact 65 of relay D to the right, through the winding of the relay D, .thus operating the relay D to its left hand position. The relay D .is similarly operated to the .left through the following circuit:beginning at the negative terminal of the battery 55, contact 53 of the relay LE to the left, contact 66 of the relay F to the right, contact 15 of the relay D to the right, through the Winding of this relay D thus operating this relay D back to its left hand normal position.

The line relays DLR and LE are next operated 'to their right hand position in which case the relay Ehis operated to its right hand position through the following circuit:-beginning at the positive terminal of the battery 46, contact 39 of the relay DLR to the right, contact 4| of the relay G to the left, contact 63 of the relay .A to the right, contact '64 of the relay '3 to the left, contact 65 of the relay C to the'right, contact 66 of the relay D to the left, contact 61 of the relay E to the left, thus causing the relay E to be operated toward the right. Similarly the relay E is moved to its right hand position through closure of the following circuit:--beginning at the positive terminal of battery 55, contact .53 of the line relay LR to the right, contact 60 of the relay F to the right, contact 15 of the relay D to the left, contacts 16 of the relay E1 to the left, through the winding of this relay E thus causing operation of the relay E1 toward the right.

The line relays DLR and LE are next operated to their left hand positions in which case the relay F is operated to its left hand position through the following circuit:beginning at the negative terminal of battery 40, contact 39 of relay DLR to the left, contact 4| of relay G to the left, contact 63 of relay A to the right, contact 64 of relay B to the-left, contact 65 of relay C to the right, contact 66 of relay D to the left, contact 61 of the relay E to the right, contact 68 :of the relay to the right, thus causing the relay F to be operated :to its left hand position. Similarly the relay F is operated to its left hand position through the following circuit: beginning at the negative terminal of the battery 55, contact 53 of the relay LE to the left, contact 60 of the relay F to the right, contact 65 of the relay D 'to theleft, contacts 16 of the relay E .to the right, contact 6| of the relay F to the right, thus causing the relay F to be operated toward its left hand position.

This operation of the relay F to its left hand position disconnects the line relay 1R from the second stepping wire through the medium of the contact 19, so that. impulses over the second stepping wires I2 and IE will not operate the line relay LR The line relay DLR is next operated to its right hand position, thereby operating the relay G to the right hand position through a circuit readily traced, bearing in mind that the relays .A to F, inclusive, assume their normal position.

It is thus seen that the. non-physical rotation of the relays MR, LR, and RLR causes the channel selecting relays .of like reference character (disregarding the exponents) to be operated successively from their normal to their dotted position, and after all .of these relays have been operated to their dotted position causes them to be operated back to their normal position sequentiallyiand in synchronism. These channel selecting relays are all at rest long enough between successive operations thereof to complete distinctive message or channel circuits, bearing in mind that although a particular channel selecting relay is shifted it .remains in the shifted position for some time but that its relation of position to the next adjacent relay is only maintained until the next succeeding relay is operated. In other words, if a circuit is taken through the right hand contacts of twoadjacent relays this circuit is only maintained from the time that the first of these relays is operated until the second of these relays is operated.

Let us now assume that the lever LS has been moved toward the left, and let us trace the channel circuit over which the relay DR is controlled by the lever LS the message channel for which is closed only while the relays A and B and the relays A and B assume their left hand positions, which can only'happen when all of the channel selecting relays "of the two groups except the relays A and A assume their normal position, which relays presumably have just been operated to their dotted position. 'This circuit maybe traced as follows:beginning at the negative terminal of the battery 25, wires'86 and 81, contact LS toward the left, wire '82, contact 83 toward the left, 'wire '84, contact 85 toward the left, wire 86, contact 81 toward the right,

wires I92, 593 and E94, back through the common return wire 53 connected to the midpoint of battery 25, so that operation of the lever LS toward the left causes the direction relay DR to be operated toward the left.

Similarly, since the lever contact I95 is meclianically connected to the lever LS the contact I05 is also operated toward the left, thereby applying current of positive polarity to the signal relay SR through the following circuit-- starting at the positive side of battery 25, in the dispatchers office, wires 25, I99, I01, and I08, contact I95, wire Hi9, contact III) of the relay B in its left hand position, wire II I, contact I I2 of the relay C in its left hand position, wire H3, contact Hi4- of the relay D in its right hand position, wire H5, contact H5 of the relay E in its left hand position, wire II I, contact 93 of the relay F in its right hand position through the wire 94, contact 23 of the relay LR in the right hand position, wire 95, contact 2| of the relay MB in its left hand position, message wire I9, wire 99 (see Fig. 1B), contact I4 in its left hand dotted position, wire III, contact 13 in its left hand position, wire H2 through the winding of signal relay SR through the wires H3, H4, I93 and I94, to common return wire I3 connected to the midpoint of battery 25.

Let us now assume that the dispatcher wishes to operate the switch machine SM to the takesiding position in response to operation of the switch machine relay SMR to its left hand position, and to accomplish this he operates the lever LSM toward the left. The circuit through which the lever LSM may operate the relay SMR, which is closed only when the relays B and C as well as the relays B and C all assume their right hand position, and may be traced as follows:-beginning at the negative terminal of the battery 25, wire 89, 3!, and I29, lever contacts LSM to the left, wire I2I, contact of the relay B in its right hand position, wire 86, contact 37 of the relay C in its right hand position, wire 88, contact 89 of the relay D in its left hand position, wire 99, contact 94 of the relay E in its right hand position, wire 92, contact 93 of the relay F in its left hand position, wire 94, contacts 23 of the relay LR in its left hand position, wire 22, contact 2i of the relay MR toward the right, message wire I9, wire 96 (see Fig. 1A), contact 14 of the relay C toward the right, wire 91, contact 98 of the relay B toward the right, wire I23, winding of the relay SMR wires I24, H4, I93, I94, common return wire I3, back to the midpoint of battery 25. The completion of this circuit operates the switch machine relay SMR toward the left, thereby operating the switch machine SM toward the take-siding position, in a manner as more clearly described in the Wight application, Ser. No. 120,423 above referred to.

Similarly, the circuit for operating the direction relay DB toward the left completed when the lever LS is moved toward the left during the period the relays E, F, E and F assume the left hand position, may be traced as follows:- beginning at the negative terminal of battery 25, wires 89, Si, 529, and I25, contact LS in its left hand position, wire I26, contact 9| of relay E toward the left, wire 92, contact 93 of relay F toward the left, wire 94, contact 23 of the relay LR. toward the left, wire 22, contact 2| of the relay MR toward the right, message wire I9, wire I28 (see Fig. 1B), contact 11 of relay F toward the left, wire I29, contact I39 of relay E toward IBI, winding of the direction relay DR through the left, wire I3I, winding of the direction relay DB wires I32, I33, I34, and I35, to common return wire I3, back to the midpoint of battery 25.

Similarly, the signal relay SR is operated to its right hand position during the short period while the relays D, E, and D and E assume their right hand position, in response to this operation of the lever LS toward the left through the following circuit:beginning at the positive terminal of battery 25, wires 29, I93, and 549, contact I4I of the lever LS wire I42, contact 99 of the relay D in its right hand position, wire 99, contact 9| of the relay E in its right hand position, wire 92, contact 93 of the relay F in its left hand position, wire 94, contact 23 in its right hand position, wire 95, contact 2i of relay MR in its left hand position, message wire I9, wire I28 at the second way station, (see Fig. 1A) contact T1 of the relay F in its left hand position, wire I29, contact I39 of the relay E in its right hand position, wire I45, contact I 45 of the relay D in its right hand position, wire Ml, winding of the signal relay SR wires I48, I34, I35 and common return wire i3, back to the midpoint of battery 25.

Similarly, the switch machine relay SMR may be operated toward its left hand dotted position by movement of the lever LSM to its left hand position, through the following circuit, closed when the relays D and E, and the relays D and E assume their left hand position:-beginning at the negative terminal of battery 25, wires 89, 8|, I29, I25 and I59, lever LSM in its left hand position, wire I5I, contact H4 of the relay D in its left hand position, wire H5, contact N5 of relay E in its left hand position, wire Hl, contact 93 of relay F in its right hand dotted position, wire 94, contact 23 of the relay LR in its left hand position, wire 22, contact 2i of relay MB in its right hand position, message wire I9, wire I28 (see Fig. 1B), contact "I? of relay F in its right hand position, wire I52, contact I53 of the relay E in its left hand position, wire I54, contact I55 of the relay D in its left hand position, wire I56, winding of the switch machine relay SMR through wires I51, I33, E34, I35, and common return wire I3, back to the midpoint of battery 25.

Let us now consider the operation in connection with transmitting the condition of occupancy of the detector track circuit containing track relay IE to the dispatchers office, by illumination of the indicating lamp P. Let us assume that the relay TR has been dropped by passing train, thereby reversing the polarity of current from the following circuit:--beginning at the negative side of the battery I99, contact I SI of the relay PR in its retracted position, wire I62, contact I93 of the relay A in its right hand position, wire I94, contact '63 of the relay B in its right hand position, wire HI, contact '14 of the relay C in its left hand position, wire 96, message wire I0, contact 2! of the master relay MR, in its left hand position, wire 95, contact 23 of the relay LR in its right hand position, wire 94, contact 93 of the relay F in its right hand position, wire H'I, contact H5 of the relay E in its left hand position, wire H5, contact H4 of the relay D in its right hand position, wire H3, contact H2 of the relay C in its left hand position, wire III, contact H9 of the relay B in its right hand position, wire i55, contact I55 of the relay A in its right hand position, wire I91, winding of indication relay 1R through common return wire I3, wires I94 and I98, back to the midpoint of battery [60. The completion of this circuit, even though only momentarily, operates the indication relay 1R toward the left thereby illuminating the indicating lamp I until the track relay TR again picks up and re-applies current of positive polarity to the indicating relay 1R Let us now see how de-energization of the track relay TR, applies current of negative instead of positive polarity to the indication relay 'IR through the momentarily completed message channel completed only when the relays E, F, and E and F all assume their right hand position. This circuit may be traced as follows: starting at the negative terminal of battery H0, contact of the track relay TR assuming its retracted position, wire I12, contact I53 of the relay E in its right hand position, wire I52, contact 11 of the relay F in its right hand position, wire I28, message wire l0, contact 2| of the master relay MR assuming its left hand position, Wire 95, contact 23 of the relay LR. assuming its right hand position, wire 94, contact 93 of the relay F assuming its right hand position, wire I I1, contact I I6 of the relay E assuming its right hand position, wire I14, winding of the indicating relay 1R to common return wire l3, wire I35 (second way station), wire I15 connected to the midpoint of battery I10. The completion of this circuit with the contact of track relay 'I'R, in its retracted position causes current of negative polarity to be applied to the indication relay 1R thereby causing its polar contact to be moved to the left to complete the energizing circuit for the indicating lamp 1 In view of the foregoing it is noted that in each case where a channel selecting relay is operated, whether in the dispatchers office or at a way station, it must break its own energizing circuit before it has completed its movement. This is not a difficult matter because the type of relay used includes a permanent magnet which tends to operate the relay contacts to their extreme position as soon as they have moved beyond their middle position. If desired the contact carrying the energizing circuit of its own relay winding may be constructed to be made until the relay has moved beyond center, that is, to be a break-beyond-center contact, so that the momentum of the armature of the relay need not be relied upon to carry it over center. The master relay MR and the line relay DLR, LR and LR are preferably biased to their neutral position as conventionally shown.

Attention is directed to the fact that each channel circuit is carried through the contact 23 of relay LE and contact 2| of relay MB. This is done in order to cut down the channel time considerably below the maximum channel time. In this connection it should be noted that the contacts 2| and 23 must be out of correspondence to complete a channel circuit, or in other words, the channels may be closed only during the time line relay LR is energized but has not yet responded to such energization. This line relay LR may be slow-acting as compared with relays RLR and MR, so that the proper channel time may be obtained.

Applicants have thus described how the various channel selecting relays 0f the bank or group may be operated in synchronism and sequentially one after the other in alphabetical order, and have pointed out the operation of these relays, and how these relays are again brought into synchronism if they should for some reason or other get out of synchronism, this being carried out by transferring from the first stepping line to the second line, so that the relay A is at each time operated when the relay A is operated for each half cycle of relay operation. Applicants have then pointed how the distinctive message channels are closed one at a time, each of which channel circuits remains closed only so long as two adjacent relays in the bank series assume like positions, it being noted that when all of the relays assume their normal position adjacent relays assume unlike polar positions and also that when all of relays assume their abnormal dotted position adjacent relays of the bank assume unlike positions, from which it appears that if the channel circuit is taken through like polarity contacts of two adjacent relays such channel is completed only during one step of the entire cycle of relay operation. It is to be understood that the arrangement shown may be extended to any number of stations instead of only two stations, as illustrated, and that any number of relays may be used at a particular way station instead of the three relays A B and C or the relays D and E and F as shown. Attention is particularly directed to the economy in relays required in the system described, in that there is only one way station channel selecting relay for each dispatchers channel selecting relay, that is, the entire relay series is not repeated at each way station, only those relays required at a particular way station are located at such way station. Putting it another way, the non-physical rotation accomplished by relays lends itself admirably to distribution of a single cycle synchronous mechanism along the entire railroad so that a single relay group may be parcelled along the entire railroad and duplication of devices is eliminated. Looking at the arrangement shown and described in a little diiTerent way, the railroad system is divided into way stations or sections with relays located at each way station in which the relays are so interconnected that first one way station is'selected, the bank of relays at that way station are successively stepped to the reverse position from what they then assumed, after which the next way station may be stepped along one after another, and so on, until all of the way stations have had the relays of their banks shifted to the reverse position from what they previously assumed.

The present invention of which only one specific embodiment has been illustrated is, of course, understood to be of broader application than the specific arrangement shown. For instance, it appears, that in accordance with the present invention, that a synchronously operated selector mechanism may be located at each of a plurality of way stations and that these synchronous selector mechanisms may be operated one at a time, by the respective line relay of the way station then being operated. Although banks of relays have been illustrated as one form of a synchronous selector mechanism usable at a way station, it should be understood that some other form of synchronous selector mechanism, such as the mechanism shown in the application of Neil D. Preston, Ser. No. 199,325 filed June 16, 1927, may be used instead of the banks of channel selecting relays shown. Also, although the particular system illustrating the present invention is one which is intended to be operated continuously except when the hand switch H7 is open, it should be understood that the system may be readily modified as disclosed in the joint application of Hitchcock and Dicke, Ser. No. 345,667, filed March 9, 1929, in which the system is normally at rest but is automatically initiated into action either when a change in traffic conditions takes place which should be indicated in the dispatchers office through suitable OS signalling means, or is initiated into action when a lever has been operated in the dispatchers oflice to enable the control of said lever to be transmitted to the particular distant way station.

Having thus shown and described one particular system for carrying out the present invention, it is desired to be understood that the particular system shown has been selected for the purpose of disclosing the underlying principles of the invention rather than its scope or the particular circuit arrangement preferably employed in practicing the same, and that certain features of the system may be omitted; for in stance, the message circuit need not be carried through the contact 23 of the relay LE and the contact 21 of the relay MR, unless desired, or the line relays LE LE etc. may be omitted in which event the stepping circuit would be connected directly to the contacts of relays A or D as the case may be, instead of to the corresponding line relays LE or LE and that various changes, modifications, and additions may be made to the particular arrangement shown to apply the system to fit the particular problem encountered in practicing the invention all without departing from the spirit or scope of the invention or the idea of means underlying the same, except as demanded by the scope of the follow- .ing claims.

What we claim is:

1. In a train dispatching system, the combination with a dispatchers ofiice and a plurality of way stations; of switch machines and signals at the way stations and indicators at said dispatchers office; and a synchronous selector system for controlling said switch machines, signals, and indicators comprising; a dispatchers channel selecting relay bank located at the dispatchers ofiice, a line relay at the dispatchers office for controlling the selecting operation of said dispatchers channel selecting relay bank, a way station channel selecting relay bank having relays corresponding in number respectively to the relays of said dispatchers channel selecting relay bank and having its relays distributed among the various way stations, a line relay for each of said way stations for controlling the selecting operation of said channel selecting relays at its respective way station, means for operating the channel selecting relays of the dispatchers channel selecting relay bank successively in a certain order, means for placing said line relays at the several way stations successively and sequentially in multiple in a line circuit with said line relay at said dispatchers ofice, whereby the way station channel selecting relays are operated sequentially and in synchronism with their corresponding channel selecting relays at the dispatchers office, and whereby the way station channel selecting relays are operated at only one station at a time, and a plurality of message circuits each including the same message and return line wires completed successively during a cycle of said channel selecting relays, each of said message circuits including contacts of two adjacent relays of the dispatchers channel selecting relay bank, and each of said message channel circuits being used to control a particular signal, indicator or switch machine.

2. A train dispatching system of the synchronous selector type for controlling tralfic controlling devices of railroads comprising, a dispatchers oflice, a plurality of way stations, a separate line relay for said dispatchers ofiice and for each of said way stations, a dispatchers channel selecting relay bank comprising a plurality of relays operated successively by and in accordance with repeated operations of said dispatchers line relay, a way station channel selecting relay bank each relay of which corresponds to a particular relay of the dispatchers relay bank these relays being distributed along the railway track in a manner to associate two or more relays with. each of said Way station line relays operating the same, means for successively connecting said way station line relays one at a time in series with said dispatchers line relay said line relays and channel selecting relays being so interconnected that upon sequential operation of the relays of the dispatchers bank by the dispatchers line relay the corresponding relays of the way station bank are operated in synchronism therewith through the medium of their associated line relay, a plurality of message circuits completed successively and each including the samelinc wire and common return wire and contacts of corresponding relays of the dispatchers bank and of the way station bank.

3. A train dispatching system of the synchronous selector type for controlling trafiic controlling devices of railroads comprising, a dispatchers ofiice, a plurality of way stations, a separate line relay for said dispatchers ofiice and for each of said way stations, a dispatchers bank of channel selecting relays operated successively by repeated operations of said dispatchers line relay. a small bank of channel selecting relays for each way station operated successively by repeated operations of the line relay of the corresponding way station, the channel selecting relays of all the small banks together constituting the way station relay bank and each relay thereof corresponding to a particular relay of the dispatchers oflice bank, means for connecting said dispatchers line relay in series with said way station line relays successively one at a time in a'manner to cause the channel selecting relays of the dispatchers relay bank to the operated synchronously with corresponding channel selecting relays of the way station relay bank, and a plurality of message circuits each including the same line and return wire and including the contacts of corresponding channel selecting relays of the dispatchers relay bank and of the way station relay bank.

4. A train dispatching system of the synchronous selector type for controlling trafiic controlling devices of railroads comprising, a dispatchers oflice, a plurality of way stations, a separate line relay for said dispatchers office and for each of said way stations, a dispatchers bank of channel selecting relays operated successively by repeated operations of said dispatchers line relay, a way station bank of channel selecting relays divided into groups to provide a group for each way station line relay, the relays of each group being controlled to be operated successively by repeated operations of such line relay, means for connecting said dispatchers line relay in series with said way station line relays successively one at a time for periods to cause the channel selecting relays of the dispatchers-relay bank to be operated synchronously with corresponding channel selecting relays of the way station relay bank, and a plurality of message circuits each including the same message wire and common return wire and contacts of two corresponding and synchronously operated channel selectin relays one of the dispatchers bank and the other of the way station bank.

5. A train dispatching system of the synchronous selector type for controlling traific controlling devices of railroads comprising a dispatchers office, a plurality of Way stations, a stepping circuit connecting said dispatchers ofiice and said way stations, a dispatchers bank of channel selecting relays of which individual relays are operated successively by repeated energize,- tions of said stepping circuit, the operation of each relay completing a circuit for operating the next succeeding relay by the next impulse, a Way station bank of channel selecting relays divided into groups to provide one group for each way station, each way station channel selecting relay corresponding to one relay of the dispatchers relay bank and the relays of the way stationbank being operated successively in response to re-, peated energizations of said stepping circuit, the operation of each relay completing a circuit for operating the next succeeding relay by the next impulse, so that corresponding relays of the dispatchers b-ankand the way station bank are operated simultaneously and always assume corresponding positions, said dispatchers relay bank and way station relay bank including means for resynchronizing the relays in the event the relays of one or the other of these banks gain or lose one or more steps, and a plurality of message circuits closed sequentially each including the same line wire and common return wire and each including contacts of two corresponding and synchronously operated channel selecting relays respectively of the dispatchers bank and the way station bank.

6. A train dispatching system of the synchronous selector type for controlling trafiic controlling devices of railroads comprising, a dispatchers office, a plurality of way stations, a separate line relay of the polar type for said dispatchers office and for each of said way stations, a dispatchers office channel selecting relay bank comprising a plurality of relays operated successively by and in accordance with the polar position of said dispatchers line relay, a way station channel selecting relay bank each relay of which corresponds to a particular relay of the dispatchers relay bank these relays being distributed along the railway track in a manner to associated two or more relays with each of said way stations and, means for successively connecting said way station line relays one at a time in series with said dispatchers line relay, said polar line, relays and channel selecting relays being so interconnected that upon sequential operation of the relays of the dispatchers bank by the dispatchers line relay the corresponding relays of the way station bank are operated in synchronism therewith through the medium of their associated line relay, a plurality of message circuits completed successively and each including the same line wire and common return wire and contacts of corresponding relays of the dispatchers bank and of the way station bank.

7. A train dispatching system of the synchronous selector type for controlling traific controlling devices, of railroads comprising, a dis patchers ofiice a plurality of way stations, a

separate polar line relay for saiddispatchers office and for each of said way stations, a dispatchers bank of channel selecting relays operated successively by repeated reversals of said dispatchers line relay, a small bank of channel selecting relays for each way station operated successively by repeated reversals of the line relay of the corresponding Way station, the channel selecting relays of all the small banks together constituting the way station relay bank and each relay thereof corresponding to a particular relay of the dispatchers office bank, means for connecting said dispatchers line relay in series with said way station line relays successively one at a time in a manner to cause the channel selecting relays of the dispatchers relay bank to be operated synchronously with corresponding channel selecting relays of the way station relay bank, and a plurality of message circuits each including the same line and return wire and including the contacts of corresponding channel selecting relays of the dispatchers relay bank and of the way station relay bank. 7 8. A train dispatching system of the synchronous selector type for controlling traflic controlling devices of railroads comprising, a dispatchers office, a plurality of way stations, a separate line relay of the polar type for said dispatchers office and for each of said way stations, a dispatchers bank of channel selecting relays operated successively by repeated reversals of said dispatchers line relay, a way station bank of channel selecting relays divided into groups to provide a group for each way station line relay, the relays of each group being controlled to be operated successively by repeated reversals of such line relay, means for connecting said dispatchers line relay in series with said way station line relays successively one at a time for periods to cause the channel selecting relays of the dispatchers relay bank to be operated synchronously with corresponding channel selecting relays of the way station relay bank, and a plurality of message circuits each including the same message wire and common return wire and contacts of two corresponding and synchronously operated channel selecting relays one of the dispatchers bank and the other of the way sta tion bank.

9. A train dispatching system for controlling the movement of trains in response to dispatcher controlled wayside signals comprising, a dispatchers ofilce, a plurality of way stations, two stepping wires, 9, message wire and a common wire connecting said dispatchers office with each of said stations successively, a dispatchers bank of polar channel selecting relays, a way station bank of polar relays divided into groups one group for each way station and one relay for each relay in the dispatchers bank, means including said two stepping wires for simultaneously operating the polar relays of the dispatchers bank and the corresponding polar relays of the way station bank to corresponding polar positions, and a plurality of sequentially closed channel circuits each including said message wire and said common wire and including corresponding polar contacts of corresponding polar relays of the two relay banks. 7

10. A train dispatching system for controlling the movement of trains in response to dispatcher controlled wayside signals comprising, a dispatchers ofiice, a plurality of way stations, a dispatchers bank of polar channel selecting relays, a way station bank of polar relays divided into groups one group for each way station and one relay for each relay in the dispatcher bank, means for simultaneously operating the polar relays of the dispatchers bank and the corresponding polar relays of the way station bank to corresponding polar positions, and a plurality of sequentially closed channel circuits each including the same line wire, common return wire and corresponding polar contacts of corresponding polar relays of the two relay banks and also in cluding contacts for restricting the time during which these channels may be completed.

11. A train dispatching system for controlling the movements of trains by controlling wayside signals at a plurality of Way stations from a central dispatchers oflice, a stepping wire connecting the dispatchers office with the plurality of way stations, a line relay at the dispatchers oflice and at each of the way stations controlled by current flowing over said stepping Wire, a group of channel selecting relays at the control office and at each of said way stations so associated with their respective line relays as to be operated sequentially in response to repeated operations of the associated line relay, means including said groups of channel selecting relays at the way stations for rendering said line relays successively responsive one at a time to current in said stepping wire to control their respective channel selecting relays, and means for controlling said wayside signals including contacts of said channel selecting relays at the dispatchers ofiice and contacts of the channel selecting relays at the particular way station where such wayside signals are located.

12. A train dispatching system for controlling the movement of trains in response to wayside signals comprising; a dispatchers office; a plurality of way stations; a stepping wire; a line relay at each way station controlled by current flow in said stepping wire; a synchronous selector mechanism associated with each of said line relays, each of said mechanisms being responsive to operate step-by-step in response to repeated operations of its associated line relay; means including the synchronous selector mechanisms at the way stations for rendering said line relays successively responsive one at a time to current in said stepping wire to thereby control their respective mechanisms; and means for controlling said wayside signals including contacts controlled by said synchronous selector mechanisms.

13. In a centralized trafiic controlling system, the combination with a central office and a plurality of way stations, of a series of channel selecting relays at each way station, a channel se' lecting relay in the central office for each way station channel selecting relay, a line relay in said central office and at each way station, means including said line relays to cause said central oflice channel selecting relays and their corresponding way station selecting relays to operate sequentially and also including a line Wire connecting adjacent way stations for causing the first channel selecting relay of a particular Way station to operate the next step after the last channel selecting relay or" the next preceding way station has been operated, and a plurality of message circuits each including channel selecting relay contacts and the same line wire rendered available sequentially to control traliic controlling devices at said way stations.

14. In a centralized trailio controlling system for railroads; the combination with a central ofiice and a plurality of way stations, of a line relay at each way station, a first line wire section connecting said central office to the first Way station, a second line wire section connecting said. first way station to the second way station, a message wire connecting said central ofiice and all of said way stations, means at said central oflice and at said way stations for closing a large number of message circuits each including said message wire sequentially and controlled by apparatus at said central ofiice and the line relays at said way stations, station selecting means at each way station for disconnecting the line relay at said Way station and connecting the line wire section toward the rear to the line wire section in advance, and other sections of line wires connecting the first way station to the central ofrlce and each way station to the next more distant way station for returning said station selecting means back to its normal position.

15. In a centralized trafiic controlling system for railroads; the combination with a central ofiice and a plurality of way stations, of a line relay at each way station, a message circuit connecting said central ofiice and all of said way stations, one line circuit divided into sections each section connecting two adjacent way stations, another line circuit also divided into sections each connecting two adjacent way stations, a line relay at each Way station, two positionmeans at each way station for either connecting the line relay at such way station to said one line circuit and connecting the adjacent sections of said another line circuit together or connecting the line relay at such way station to said another line and connecting the adjacent sections of said one line circuit together, whereby the line relay at each way station may be individually connected to either said one or said another line circuit and a railway signal at each way station controlled over said message wire through the medium of said line relays.

16. In a centralized traflic controlling system for railroads; the combination with a central oflice and a plurality of way stations, of a line relay at each way station, a message circuit connecting said central office and all of said way stations, one line circuit divided into sections each section connecting two adjacent way stations, another line circuit also divided into sections each connecting two adjacent way stations, 2, line relay at each way station, two position means at each way station for either connecting the line relay at such way station to said one line circuit and connecting the adjacent sections of said another line circuit together or connecting the line relay at such Way station to said another line and connecting the adjacent sections of said one line circuit together, and means for effecting successive operation of said two position means to cause the line relays of said way stations to be successively connected to said one line circuit and then successively connecting to said another line circuit and a railway signal at each way station controlled over said message wire through the medium of said line relays.

17. A train dispatching system for controlling the movement of trains in response to dispatcher controlled wayside signals comprising, a dispatchers ofiice; a plurality of way stations; a message wire and a common return wire connecting said dispatchers ofiice with each of said Way stations, a dispatchers bank of polar channel selecting relays with each relay having a plurality of polar contacts; a way station bank of polar relays divided into groups, one group for each way station,

one relay for each relay in the dispatchers bank, and each relay having a plurality of polar contacts; means for simultaneously operating the polar relays oi the dispatchers bank and the corresponding polar relays of the way station bank to corresponding polar positions, a plurality of sequentially closedchannel circuits, each including the said message wire and said common return wire and corresponding polar contacts of corresponding polar relays of said two relay banks; and means in the dispatchers office for allowing closure of said channel circuits only for a time shorter than the time during which said polar contacts are closed.

18. A train dispatching system for controlling the movement of trains in response to dispatcher controlled wayside signals comprising, a dispatchers office; a plurality of way stations; two stepping line wires, a message line wire and a common return line wire connecting said dispatchers ofiice with each of said way stations successively; a dispatchers bank of polar channel selecting relays being operable through cycles of operation; a way station bank of polar channel selecting relays divided into groups, one group for each way station, and one relay for each relay in the dispatchers bank, said way station bank being operable through cycles of operation; means for simultaneously operating the polar relays oi the dispatchers bank and the corresponding polar relays of the way station bank to corresponding positions, said means including one of said two stepping line wires during the first half of each cycle, and said means including the other of said two stepping line wires during the last half of each cycle; and a plurality or sequentially closed channel circuits, each including said message line wire, said common return line wire, and corresponding polar contacts of corresponding polar relays of the two relay banks.

19. In a traiiic controlling system of the multiple impulse type for railroads, the combination with a central office, a plurality of field stations, a line wire connecting said ofiice and the first field station which may be extended successively to more remote field stations, a line relay at each field station, a line relay at said central office, a series of stepping relays at each field station, a series of stepping relays at said ofilce, control circuits for said stepping relays controlled by actuation of the associated line relay in a manner to cause a field stepping relay to be actuated in synchronism with a corresponding stepping relay in said ofiice, means governed by the last stepping relay of each field station relay series for extending said line wire to the next more distant station.

20. In a centralized trafiic controlling system, a central office, a plurality of successively more remote field stations, a sectionalized line circuit the sections of which extend respectively from the central ofiice to the first field station and from each station to a more remote station, a line relay in said line circuit at said central ofiice, a line relay at each field station included in the section of line circuit extending from that station to the next less remote station, a series of stepping relays at said ofiice and at each field station each series controlled by its associated line relay, and means including said stepping relays at said field stations for successively connecting the next section of said line circuit to the next preceding section of line circuit extending to the central ofiice.

21. A centralized trafilce control system for transmitting controls and indications between a control office and a plurality of field stations comprising, a stepping line circuit organization including a line wire extending from the control office to the nearest station and from each station to the next more remote station, a series of stepping relays in the control ofiice, a plurality of stepping relays at each field station, a line relay in the control ofiice and a line relay at each field station respectively controlling the corresponding stepping relays, said line wire at the beginning of a cycle of stepping operation extending to the first station nearest the control office only, and means controlled by the last stepping relay at each station for extending said line wire to the next more remote station to control the line relay at that next station, whereby the stepping relays at each of the plurality of stations are operated only one station at a time beginning with the station nearest the control ofiice in synchronism with corresponding relays of said series in the control office.

22. In a centralized traific control system, in combination with a series of stepping relays in a control ofiice and a plurality of stepping relays at each of a plurality of field stations, a stepping line circuit organization comprising line wire sections respectively extending from the control ofiice to the nearest station and from each station to the next more remote station, a line relay in said line circuit at the control office, a line relay at each station included in the line wire section extending toward the control ofiice, means for sequentially energizing the stepping relays at each station in response to the operation of its line relay, means for sequentially energizing the series of stepping relays in the control office in response to the operation of the line relay in the control ofiice, and means governed by the last stepping relay at each station for connecting said line wire sections to extend the line circuit to the next station more remote from the control office, whereby the stepping relays at each station in turn are operated sequentially in synchronism with certain corresponding stepping relays in the control ofiice.

23. A normally-at-rest centralized traffic control system of the multiple impulse type for transmitting controls and indications between a conrol cfiice and a plurality of field stations one at a time in succession comprising, a line circuit organization effective upon initiation of the system to provide a line circuit extending to the first station nearest the control ofiice only, said line circuit organization including line wire sections extending from each station to the next more remote station, a polar line relay in each station included in the polar line section extending toward the control office, a plurality of stepping relays at each station operated sequentially in response to a series of successive impulses applied to said line circuit when extended to that station, and means at each station responsive to the last impulse of the series for that station for disconnecting the line relay at that station from said line circuit and extending said line circuit to the next more remote station.

OSCAR H. DICKE. FOREST B. HITCHCOCK. 

